Illuminated push button switch with rotary latching means



Aug. 15, 1961 B. D. M MAINS 2,996,593

ILLUMINATED PUSH BUTTON SWITCH WITH ROTARY LATCHING MEANS Filed Jan. 27,1959 INVENTOR. BILLY D. M MAINS B OP W A T'TORNEY United States Patent2,996,593 ILLUMINA'DED PUSH BU'ITON SWITCH WITH ROTARY LATCI-IING MEANSBilly D. McMains, Anaheim, 'Calif., assignor to Marco IndustriesCompany, Anaheim, Calif., a corporation of California Filed Jan. 27,1959, Ser. No. 789,324 14 Claims. (Cl. 200-159) This invention relatesto push button switches in general and in particular to a combination ofand indicator light which I choose to designate generally as anilluminated push button switch. The general object of the presentinvention is to provide an improved push button switch adapted, inresponse to depression of its push button from a normally open position,to become self latched in closed position and, in response to a furtherdepression of the push button, to be self releasing back to its normallyopen position.

More particularly, the invention aims to provide a push button switchhaving latching means embodying a rotary latching part including acombined latching and camming finger cooperating with a track in thehousing of the device, for actuation from switch open to switch closedposition and vice versa upon successive depression and release of thepush button of the device.

A further object is to embody such a latching switch in combination withan illuminated lens cap as the embodiment of the push button part of thedevice, together with dual circuits to the switch and to bulb of thedevice, both circuits utilizing conductors which enter the rear end ofthe device, with the illuminating circuit bypassing the switch.

A further object is to provide such a device wherein a switch housinghas at one end a mounting for the switch and its electric terminals andat its other end is provided with a tubular neck in which a switchactuator plunger is slidably mounted, said neck further being providedwith means for mounting the entire unit in an opening in an instrumentpanel or the like.

' Other objects and advantages will become apparent in the ensuingspecification and appended drawing in which: FIG. 1 is a side View of anilluminated push button switch unit embodying the invention, with theswitch housing and switch parts shown in axial section;

' FIG. 2 is an axial sectional view of the same taken on the line 2-2 ofFIG. 1;

-FIG. 3 is a fragmentary side view of the same, showing the switchhousing from the outside with a portion broken away and shown in sectionto illustrate the camming mechanism;

FIG. 4 is a transverse sectional view taken on the line 4-4 of FIG. 2;and

FIG. 5 is an end view of the unit.

Referring now to the drawings in detail, there is shown therein as anexample of one formin which the invention may be embodied, anilluminated push button switch embodying in general, a housing A, aswitch unit B mounted in the rear end of the housing A, a combinedswitch actuator plunger and light casing C slidable in housing A andembodying a combined push button and lens cap unit on its outer end, alight assembly D mounted within the casing C, and rotary latchingmechanism E including a rotary latching part on the inner end of plungerC and combined guide and latch detent means embodied in the housing A.

The following detailed description of the invention will take up thesemain units of the device in the order enumerated above;

The housing A."Housiug A embodies at its rear end a cylindrical switchhousing and at its forward end a the illuminating light a reducedcylindrical tubular barrel or neck -11 the end of push button switchconsist in any form of push stem.

which is threaded at 12. An annular flat radial shoulder 13 joins theneck 11 to the switch housing 10. A series 15 of retainer and lock nutsand interposed washer are threaded onto the threaded section 12 of neck11 to secure the unit to a mounting panel, with the neck 11 extendingthrough an opening therein.

In the rear end of housing 10 is a terminal and switch mountinginsulator means comprising a switch mounting insulator cup 16 ofcylindrical cup form to which is secured, as by bonding, a terminalinsulator spider 17 having two pairs of recesses 18 (disposed at spacingaround the circumference thereof) in which are received, respectively, apair of diametrically opposed switch terminals 2'1, 22 and a pair ofdiametrically opposed illuminating circuit terminals 19, 20, the latterbeing arranged at 90 spacing from terminals 21, 22.

Spider 17 has an integral collar portion 23 which extends into the rearend of switch housing 10 and has a thickened cylindrical rim snuglyfitted within housing 10 and seated against a flange 25 which is spuninwardly at the rear end of housing 10 and holds the parts in assembly.To illustrate the integral connection between spider 17 and collar 23,FIG. 2, at its lower right corner shows a section through one of thecorner segments intervening between recess '18. Recesses 18 are openthrough the web between spider 17 and collar 23, so that the terminals19-22 can be assembled.

Within switch housing 10, and held between the inner end of collar 23and the shoulder 13 of the housing, is a cam sleeve 24 of insulatingmaterial which is fairly hard and wear resistant (e.g. nylon). Formed inthe sleeve 24 are the latching detents and guide tracks which will bedescribed more in detail as part of the latching mechanism E.

The specific features of switch B form no part of the invention. It maybe of any type, either normally open or normally closed, embodying amovable contact which is yieldingly biased to a normal position andactuated to an alternate position by pressing lens cap D.

Switch B.-For example, it may be of the W-blade type, includingprimarily a stamped ring sheet metal part 26 embodying a spring arm 27carrying a movable contact 28, and a fixed contact 29 having a stemriveted through the bottom of switch mounting cup 16 and through aradial leg of terminal 19 to secure the latter in assembly. The switchpart 26 may be mounted on a metal disc 31 which in turn is shown assecured by rivets including the rivet 32 to the bottom of mounting cup16, the rivet 32 extending through the radial leg of terminal 21 andsecuring the latter in assembly.

Such a switch unit may also include a switch actuator part mountedbetween cup 16 and an insulator washer 33,

including a spring finger carrying a button 36 in engage/ ment with theswitch arm 27, and, at the axis of the assembly, having a bearing pad 37extending loosely into an aperture in the center of washer 33 andengaged by a pressure pin 38 which is slidably mounted in a bearing onthe end of a radially inwardly extending arm 39 on terminal 19. Thisbearing is received in a central aperture of an insulator washer 40which rests against terminal arm 39 and against an offset portion 41 ofterminal 20, from which a contact blade 42 extends through an aperturein washer 40. A small coil spring 43 surrounds pressure pin 38 and isengaged under compression between the end of contact arm 39 and a cuppedhead 44 of pin 38. A second coil spring '45 is engaged under compressionbetween the head 44 and the plunger assembly C which will now bedescribed.

Plunger and light assembly C.Plunger unit C may As shown, it includes acap section 49. A cup-shaped lens 53 of light transmitting material suchas translucent molded plastic material is secured to the forward end oflight casing section 49 by a mounting collar 54.

Light assem'bly D.-Secured in the rear end of light causing 47, as bystaking, is a lamp base disc 55 of insulating material to which issecured, by means of a grommet 56, a lamp socket 57 which supports anilluminating light bulb 58.

The forward end of spring 45 is engaged in a cupped head on the rear endof grommet 56 (preferably a separate cupped washer secured by the swagedrear end of grommet 56). Slidably mounted in the grommet 56 is a contactpin. 60 having at its forward end a contact head engaged yieldingly by acoil spring 61 bearing against the forward end of grommet 56 and therebyyieldingly. maintained in engagement with the tip contact of lamp bulb58. An electrical connection to the tip contact of bulb 58'is thusestablished through contact pin 60, metal grommet 56, spring 45, pusherpin 38, and terminal arm 39 to the terminal 19 in one side of theilluminating circuit. Connection to terminal 20 in the other side of theilluminating circuit is provided by the yielding engagement of contactblade 42 against a small contact brush 62 attached to the socket. Blade42 extends through an aperture 63 in the lamp base 55, and the contactbrush 62 may also extend into the aperture 63 as shown.

Rotary latching mechanism E.A latch ring 65 is mounted in an annularbearing channel 66 on the rear end of light casing section 47, forswivelling movement on the major axis of the device, and carries a pairof diametrically opposed radially projecting latch fingers 67 ofcylindrical rod form. Fingers 67 extend into respective camming tracks68 (FIGS. 2 and 3) in the form of closed-loop internal grooves in thecam sleeve 24, and are adapted to latch behind respective detents 69consisting in integral projections on sleeve 24 in the centers of therespective tracks 68 and defining the inner bearing,

surface margins of the tracks. Referring now to FIG. 3,

each track has an apex portion defining a retainer pocket.

70 in which the; respective latch finger 67 is retained to hold theplunger C in anormal, retracted position against the yielding retractingforce of coil spring 43. In this retracted position of the plunger C,the pusher pin 38 is retracted and the switch B is open, the free lengthof the coil spring 45 (stilfer than coil spring 43) being so related tothe length of the pin 38 as to permit such retraction of the pin 38.

Each cam track further includes, on one side thereof (the right side asviewed in FIG. 3) a ramp portion 71 the inner side of which is definedby a ramp surface on detent 69 which engages the respective latch finger67 as the plunger C is depressed and guides the finger 67 past this.

side of the detent, the latch ring 65 swivelling in one direction tofollow the movement of the latch fingers. As the respective finger 67passes this side of the detent 69, it is engaged by an outer rampsurface of a portion 72 of the track and thereby guided toward thereturn side of the track to a position behind the detent 69, the ring 65swivelling in the opposite direction. At this point, the respectivelatch finger is engaged by a stop shoulder 73 in the respective track,thus arresting this stage of movement of the finger at a point behindthe detent 69, so that, upon release of the pressure against the plungerC, the finger will be retracted, under the loading of spring 43, intoengagement with the rear side of detent 69. This rear side embodies aramp 74' having an inclination opposite to that of ramp 72, whereby thespring loaded engagement of the finger 67 thereagainst results infurther movement of the respective latch finger 67 toward, the returnside of the track, clearing the stop shoulder 73, until the fingerengages ina retaining pocket 75 of detent 69, where it will be retainedso as to hold the plunger C in a depressed position. In this position,the pusher pin 38 will be projected rearwardly, the yielding resistanceof coil spring 43 being overcome by the greater resistance of coilspring 45, and the switch B will thereby be closed, the projectingmovement of pin 38 being transmitted through bearing pad 37 to springblade 35 of the switch. actuator, and the blade 35 thereby being flexedrearwardly to transmit movement from button 36 to switch arm 27, therebyshifting the movable switch contact 28 into engagement with the contact29. Thus a circuit is established across switch terminals 21, 22 toclose the circuit that is controlled by the device.

Each camming track 68 further includes a ramp- 76, extendingsubstantially as a parallel continuation of ramp 72 beyond stop shoulder73, and functioning when en.- gaged by the respective cam finger 67 upona further depression of plunger C, to shift the respective latch finger67 further toward the return side of the track, until it engages a stopsurface 77 at the margin of said return side, andextending parallel tothe major axis of the device in spaced relation to the adjacent side ofdetent 69. so as to guide the respective finger 67 past this side of thedetent. in a retracting movement of the plunger C in response to. thespring loading of coil spring 43 when the manual pressure of the seconddepression of the plunger is released. The finger 67 will then engage areturn ramp 78 which will guide the finger back to the retaining pocketIn those portions 71 and 78 of the track which adjoin the retainingpocket 70, the outer ramp surfaces are parallel to the opposed surfacesof detent 69 defining the inner surfaces of these ramp portions of thetrack.

Operation-The operation of the apparatus has been described in detailin, connection with the foregoing description of the apparatus, and willbe reviewed here only in a general way. The illuminating circuit throughterminals 19, 20 to light bulb 58 may be constantly energized toilluminate the lens 53 constituting the push button part of the switchmechanism. In many cases a legend will be imprinted on the face of lens53 to designate the character and function of the particular switch in amultiple circuit system, and the illumination will facilitate thereading of the legend. When the operator desires to close the particularcircuit controlled by the device, he presses against the lens 43,projecting the plunger C rearwardly against the light yieldingresistance of spring 38, and causing the latch fingers 67 to ride in therightward side of tracks 68- as viewed in FIG. 3, until furtherdepression of the plunger is arrested by engagement of fingers 67against stop shoulders 73. In the depression of the plunger C, thespring 45, overriding the lighter spring 43, will project the pusherplunger 38 to close the switch B. Upon releasing the pressure againstlens 43, the plunger will be retracted by spring 38 and fingers 75 willengage detent 69 and advance to the pocket 75 thereof where theretracting movement of the plunger will be arrested. This-retractingmovement of the plunger is insufiicient to permit the reopening ofswitch B, which will be held closed by the latching of the plunger.

When the operator desires to open the switch, he simply presses againstthe push button-lens 43 a second time, projecting the latch fingers 67against ramps 76 which shift them into the return portions of therespective tracks 68 and against return side 77 thereof. The pressureagainst the plunger is then released, and it will be shifted by springplunger to a retracted position in which said switch is in one position;said plunger having a projecting outer end terminating in a push buttonand at its inner end being associated with said switch for actuating thesame to an alternate position when depressed; means pivotally mounted onsaid plunger near its inner end for oscillating movement with respect tothe plunger about the major axis thereof, said last means having alatching finger projectingrradially outwardly; means fixed to the innerwall of said housing providing an inwardly facing latching detent forengaging said finger to hold said plunger in depressed, switch-actuatingposition, and an internal, inwardly facing camming track ofclosed-circuit form surrounding said detent and including meanscooperable with said finger during depression of said plunger, to guidesaid finger from a starting position past one side of said detent to aposition behind the detent from which, upon release of the plunger, thefinger will be received and held by the detent in the switch actuatingposition, said camming track further including means, operative upon afurther depression of the plunger, to guide the respective fingercircumferentially to a position clearing the other side of the detent sothat, upon release of the plunger, it will be returned by said yieldingloading means to said retracted position, with said finger passing saidother side of the respective detent and returning to said startingposition.

2. In an illuminated push button switch: a tubular housing comprising atone end a switch housing portion and at its other end an open, reducedtubular neck; a switch mounted in said switch housing portion; a tubularplunger slidable axially in said neck, projecting through the open endthereof; means yieldingly loading said plunger to a retracted positionin which said switch is released to a normal position; said plungerhaving at its outer end a combined push button and lens cap, and havingits inner end arranged to actuate said switch to an alternate positionupon depression thereof; a light bulb in said tubular plunger in aposition to illuminate said lens cap; electrical connections to saidlight bulb past said switch; means pivotally mounted on the inner end ofsaid plunger and having a camming and latching finger projectingradially therefrom for oscillating movement with respect to the plungerabout the major axis thereof, said housing having an internal, inwardlyfacing camming track of closed circuit form receiving said finger and alatching detent surrounded by said track and defining a latching pocketin which said finger is receivable to latch said plunger in itsdepressed position, said camming track including means to guide saidfinger from a starting position in which said plunger is retracted, pastone side of said detent during depression of said plunger, to a positionbehind said detent'whereby upon release of said plunger said finger willbe retracted by said yielding loading into the latching recess to holdthe plunger in switch actuating position, and said track furtherincludingmeans operative upon further depression of the plunger, toguide said finger circumferentially to a position clearing the otherside of the detent so that, upon release of the plunger, it will bereturned by said yielding loading means to its retracted position, withsaid finger passing said other side of the detent and returning to saidstarting position.

3. In an illuminated push button switch: a tubular housing comprising atone end a switch housing portion and at its other end an open, reducedtubular neck; a, switch mounted in said switch housing portion, saidswitch including a fixed contact, a movable contact and.

a spring arm carrying said movable contact and normal 1y holding it inan open position; a tubular plunger slidable axially in said neck,projecting through the open end thereof, having at its outer end acombined push but- 7 ton and lens cap, and having at its inner end, aprojection to engage said spring arm during depression thereof, to closesaid switch; a light bulb in said tubular plunger in a position toilluminate said lens cap; electrical connections to said light bulb pastsaid switch; means yieldingly loading said plunger to a retractedposition in which said switch is released to its open position; alatching ring pivotally mounted on the end of said plunger and havingdiametrically opposed camming and latching fingers projecting radiallytherefrom, said housing having a pair' of diametrically opposed cammingtracks of closed circuit form receiving respective fingers, and latchingdetents surrounded by the respective tracks and defining respectivelatching pockets in which respective fingers are receivable to latchsaid plunger in its depressed position, each camming track includingmeans to guide a respective fingerfrom a starting position in which saidplunger is retracted, past one side of a respective detent duringdepression of said plunger, to a position behind a respective detentwhereby upon release of said plunger said fingers will be retracted bysaid yielding loading into the respective latching recesses to hold theplunger in switch closing position, and each track including meansoperative upon further depression of the plunger, to guide therespective finger circumferentially to a position clearing the otherside of the respective detent so that, upon release of the plunger, itwill be returned by said yielding loading to its retracted position,with said finger passing said other side of the respective detent andreturning to said starting position.

4. In a push button switch: a tubular housing comprising at one end aswitch housing portion and at its other end an open, reduced'tubularneck; a switch mounted in said switch housing portion; a plungerslidable axially in said neck; means yieldingly loading said plunger toa retracted position in which said switch is released to a normalposition; said plunger projecting through the open end of said neck,having at its outer end a push button and having its inner end arrangedto actuate said switch to an alternate position upon depression thereof;means pivotally mounted on the end of said plunger and havingdiametrically opposed camming and latching fingers projecting radiallytherefrom, said housing having a pair of diametrically opposed cammingtracks of closed circuit form receiving respective fingers and latchingdetents surrounded by the respective tracks and defining respectivelatching recesses in which respective fingers are ing depression of saidplunger, to a position behind a respective detent whereby upon releaseof said plunger said fingers will be retracted by said yielding loadingvinto the respective latching recesses to hold the plunger inswitch-actuating position, and each track including.

means operative upon further depression of the plunger, to guide therespective finger circumferentially to a position clearing the otherside of the respective detent so that, upon release of the plunger, itwill be returned by said yielding loading to its retracted position,'with said finger passing said other side of the respective detent andreturning to said starting position.

5. A switch as defined in claim 4, including an annular external bearingchannel on the inner end of said plunger, and in which said pivotallymounted means comprises a latching ring rotatably mounted in saidchannel for rotation on the major axis of said plunger.

6. A switch unit as defined in claim 4, wherein said neck and plungerare cylindrica-Lsaid neck is threaded at said forward end of the' neckfor mounting the same in;

end. an open, reduced tubular neck; a switch mounted in said switchhousing portion, said switch including a fixed contact, a movablecontact and a spring arm carrying saidvmovablecontact and biasing ittoward a normal position; a plunger slidable axially in said neck,projecting through the open end thereof, having at its outer end acombined push button and lens cap, and having its inner end arranged toactuate said switch to an alternate position; means yieldingly loadingsaid plunger to a retracted position in which said switch is released toits normal position; a circular external bearing channel on the rear endof said plunger; a latching ring swivelled in said channel and havingdiametrically opposed camming and latching fingers projecting radiallytherefrom, said housing having-a pair of diametrically opposed cammingtracks of closed circuit form receiving respective fingers and latchingdetents surrounded by the respective tracks and defining respectivelatching pockets in which respective fingers are receivable to latchsaid plunger in its depressed position, each camming track includingmeans operative, in response to initial depression of the plunger, toguide a respective finger from a starting position in which said plungeris retracted, past one side of a respective detent during depressingmovement of said plunger, to a position behind a respective detentwhereby upon release of said plunger said fingers will be retracted bysaid yielding loading into the respective latching recesses to hold theplunger in switch-actuating position, a stop shoulder to arrest saidinitial plunger depression at a point where the respective latchingfinger has'arrived at said position behind the respective detent, andeach track including means operative, upon further depression of theplunger, to guide the respective finger circumferentially to a positionclearing the other side of the respective detent so that, upon releaseof the plunger, it will be returned by said yielding loading to itsretracted position, with said finger passing said other side of therespective detent and returning to said starting position.

9. In an illuminated push button switch device: a tubular housingcomprising at one end a cylindrical switch housing and at its other endan open, reduced tubular neck; a cylindrical sleeve of insulatingmaterial lining the forward part of said switch housing portion andhaving a pair of diametrically opposed internal camming tracks of closedloop form and respective latching detents surrounded by the respectivetracks; terminal and switch mounting insulator means including acylindrical collar part mounted in the rear portion of said switchhousing and retained against the rear end of said sleeve and defining acentral switch cavity; a switch mounted on said insulator means in saidcavity, said switch including a fixed contact, a movable contact and aspring arm carrying the latter and normally holding it in an open position; a pair of switch terminals mounted on said insulator means andconnected respectively to said contacts; a tubular plunger slidableaxially in said neck, projecting through the open end thereof, having atits outer end a combined push button and lens cap, and having at itsinner end a lamp mounting base of insulating material; a lamp socket anda central lamp contact co-axially mounted on said base; a pair of lampterminals mounted on said insulator means at 90 circumferential spacingfrom respective switch terminals, one of said lamp terminals having atits innerend, a radiallyinwardly projecting arm and the other having atits inner end. a contact brush olfset radially inwardly and. projecting:forwardly alongside of and havinga sliding electrical connection withsaid lamp socket providing one side of an illuminating circuit, saidlamp mounting base having an aperture through which said brush extends;means arranged to transmit switch closing movement from said lampmounting base to said movable switch arm in response to depression ofsaidplunger and also providing a conductor connection between saidcentral lamp contact and said one lamp terminal constituting the otherside of said illuminating circuit; means yieldingly loading said plungerfor return to a normal, retracted position when released; an annularbearing channel on the inner end of said plunger; a latching ringswivelled in said channel and having diametrically opposed camming andlatching fingers projecting radially therefrom, said housing having apair of diametrically opposed camming tracks of closed circuit formreceiving respective fingers and latching detents surrounded by therespective, tracks and defining respective latching pockets in whichrespective fingers are receivable to latch said stem in its depressedposition, each camming track including means operative, in response toinitial depression of the plunger, to guide a respective finger from astarting position in which said plunger is retracted, past one side of arespective detent during depressing movement of said plunger, to aposition behind a respective detent whereby upon release of said plungersaid fingers will be retracted by said yielding loading into therespective latching recesses to hold the plunger in switch closingposition, a stop shoulder to arrest said initial plunger depression at apoint where the respective latching finger has arrived at said positionbehind the respective detent, and each track including means operative,upon further depression of the plunger, to guide the respective fingercircumferentially to a position clearing the other side of therespective detent so that, upon release of the plunger, it will bereturned by said yielding loading to its retracted position, with saidfinger passing said other side of the respective detent and returning tosaid starting position.

10. In an illuminated push button switch: a tubular housing comprisingat one end a cylindrical switch housing portion and at its other end anopen, reduced tubular neck; a cylindrical sleeve of insulating materiallining the forward part of said switch housing portion and having a pairof diametrically opposed internal camming tracks of closed loop form andrespective latching detents surrounded by the respective tracks;terminal and switch mounting insulator means including a cylindricalcollar part mounted in the rear portion of said switch housing andretained against the rear end of said sleeve and defining a centralswitch cavity; a switch mounted on said insulator means in said cavity,said switch including a fixed contact, a movable contact and a springarm carrying the latter and normally holding it in one position; a pairof switch terminals mounted on said insulator means and connectedrespectively to said contacts; a tubular plunger slidable axially insaid neck, projecting through the open end thereof, having at its outerend a combined push button and lens cap, and having at its inner end alamp mounting base of insulating material; a lamp socket and a centrallamp contact coaxially mounted on said' base; a pair of lamp terminals.mounted on said insulator means at circumferential spacing fromrespective switch terminals, one of said lamp terminals having at itsinner end a radially inwardly projecting arm terminating in a bearingcoaxial with the major axis of the switch and the other having at itsinner end a contact brush offset radially inwardly and projectingforwardly alongside of and having a sliding electrical connection withsaid lamp socket, said lamp mounting base having an aperture throughwhich said brush extends; a pusher pin slidably mounted in said bearing,having an abutment head at its forward end and arranged to transmitswitch actuatingmovement to said movable switch arm; a relatively heavycoil spring engaged between said abutment head and saidl'arnp mountingbase and adapted to transmit switchactuating movement to said pusher pinin response to depression of said plunger; a relatively light coilspring 9 surrounding said pusher pin and engaged under compressionbetween said abutment head and said bearing and loading said plunger forreturn to a normal, retracted position when released; said pusher pinand relatively heavy coil spring cooperatively providing an electricalconnection between said central lamp contact and said one lamp terminalwhile said brush provides an axially slidable electrical connectionbetween said lamp socket and said other lamp terminal; a pair ofdiametrically opposed latching fingers pivotally mounted on said plungernear its inner end and projecting radially; said housing having thereina pair of diametrically opposed latching detents for engaging saidfingers to hold said plunger in depressed, switch-actuating position andcamming tracks of closed-circuit form surrounding the respectivedetents; each of said detents providing a latching pocket in which arespective finger is receivable to latch said plunger in its depressed,switch closing position, and each of said camming tracks including meanstoguide said finger from a starting position in which said plunger isretracted, past one side of said detent during depression of saidplunger, to a position behind said detent whereby upon release of saidplunger said finger will be retracted by said yielding loading into thelatching recess to: hold the plunger in switch closing position, andsaid track further including means operative upon further depression ofthe plunger, to guide said finger circumferentially to a positionclearing the other side of the detent so that, upon release of theplunger, it will be returned by said yielding loading to its retractedposition, with said finger passing said other side of the detent andreturning to said starting position.

11. A switch device as defined in claim 10, further including a switchactuator engaged by the rear end of said pusher pin and arranged totransmit switch closing movement to said spring switch arm in responseto rearward movement of said pusher pin.

12. In a push button switch: a housing; a switch mounted in one endthereof; a plunger slidable axially in the other end of said housing;means yieldingly loading said plunger to a retracted position in whichsaid switch is in one position; said plunger having a projecting outerend terminating in a push button and at its inner end being associatedwith said switch for actuating the same to an alternate position whendepressed; means pivotally mounted on the said inner end of said plungerfor oscillating movement with respect to the plunger in a radial planeabout the longitudinal axis of the plunger, said means havingdiametrically opposed camming and latching fingers projecting radiallyoutwardly therefrom; means fixed to said housing providing a pair ofdiametrically opposed internal camming tracks of closed circuit formreceiving respective fingers and latching detents surrounded by therespective tracks and defining respective latching recesses in whichrespective fingers are receivable to latch said stern in its depressedposition, each camming track including means to guide a respectivefinger from a starting position in which said plunger is retracted, pastone side of a respective detent during depression of said plunger, to aposition behind a respective detent whereby upon release of said plungersaid fingers will be retracted by said yielding loading into therespective latching recesses to hold the plunger in switch-actuatingposition, and each track including means operative upon furtherdepression of the plunger, to guide the respective fingercircumferentially to a position clearing the other side of therespective detent so that, upon release of the plunger, it will bereturned by said yielding loading to its retracted position, with saidfinger passing said other side of the respective detent and returning tosaid starting position.

13. A push button switch as defined in claim 1, wherein said switch isnormally open and is closed by depression of said plunger.

14. In a push button switch: a housing; a switch mounted in one endthereof; a plunger slidable axially in the other end of said housing;means yieldingly loading said plunger to a retracted position in whichsaid switch is in one position; said plunger having a projecting outerend terminating in a push button and at its inner end being associatedwith said switch for actuating the same to an alternate position whendepressed; means pivotally mounted on the said inner end of said plungerfor oscillating movement with respect to the plunger in a radial planeabout the longitudinal axis of the plunger, said means havingdiametrically opposed camming and latching fingers projecting radiallyoutwardly therefrom; means fixed to said housing providing a pair ofdiametrically opposed internal camming tracks of closed circuit formreceiving respective fingers and latching detents surrounded by therespective tracks and defining respective latching recesses in whichrespective fingers are receivable to latch said stem in its depressedposition, each camming track including means to guide a respectivefinger from a starting position in which said plunger is retracted, pastone side of a respective detent during depression of said plunger, to aposition behind a respective detent whereby upon release of said plungersaid fingers will be retracted by said yielding loading into therespective latching recesses to hold the plunger in switchactuatingposition, and each track including means operative upon furtherdepression of the plunger, to guide the respective fingercircumferentially to a position clearing the other side of therespective detent so that, upon release of the plunger, it will bereturned by said yielding loading to its retracted position, with saidfinger passing said other side of the respective detent and returning tosaid starting position, said pivotally mounted means being in the formof a ring, said latching fingers being in the form of pins mounted insaid ring at diametrically opposite points, and said plunger having atits inner end an annular peripheral bearing channel receiving said ringfor oscillating movement therein.

References Cited in the file of this patent UNITED STATES PATENTS1,352,889 Gallo et a1. Sept. 14, 1920 2,671,354 Goos Mar. 9, 19542,847,559 Harrington et al Aug. 12, 1958

